#include <stack>
#include <iostream>
#include <fstream>
#include <string>
#include <cmath>
#include <sstream>
#include <iomanip>
using namespace std;

class BieuThuc
{
	string m_TrungTo;
	string m_HauTo;
	float m_fKQ;
	stack<char> stack1;
	stack<float> stack2;
	bool m_bValid;
public:
	BieuThuc() { m_fKQ = 0; m_bValid = 1; };
	void input(string a) { m_TrungTo = a; m_bValid = 1; };
	float outputKQ() { return m_fKQ; };
	string outputHT() { return m_HauTo; };
	int Check() { return m_bValid; }
	void BienDoiHauTo();
	void tinhKQ();
};
bool SoSanh(char a, char b);
float ChuoiThanhSo(string s);

